BMW N54 COBB AccessPORT Now Supports Alternate Fuels - E85

COBB Tuning is proud to announce that BMW N54 AccessPORT users can now tune for alternate fuels, such as E85, with the latest updates in AccessTUNER Race and AccessTUNER Pro tuning software. AccessPORT end-users and professional tuners can quickly update AccessPORT maps to accommodate fuels of different specific energy using the newly added Fuel Scalar tables, resulting in proper fuel trims during engine operation. This development opens the door for BMW N54 enthusiasts looking to take advantage of the performance and cost benefits of using E85 and other fuel blends.

Prior to this development, BMW N54 enthusiasts were limited to the extent they could blend E85 with regular gasoline and still have the engine operate safely within the window that the ECU fuel trims could accommodate. By giving end-users and professional tuners the ability to manipulate fuel scalars on their own, this limitation has been removed, allowing the ECU to operate with alternate fuels in the same way it does with traditional gasoline and maintain fuel trims within a range of 1%-3% while producing impressive power gains with excellent power delivery characteristics.

A Fuel Scalar table is assigned to each cylinder bank in the AccessTUNER software. For most ECUís, these tables are simple one-dimensional scaling factors that allow the user to adjust the fuel scaling up or down as needed. In the 1M ECU, the fuel scalar tables are two-dimensional 16x16 tables that scale fuel based on engine RPM and load.

Non-1M ECU Fuel Scalar Table

1M ECU Fuel Scalar Table

Due to variation in fuel blends across the country, E85 Off-The-Shelf maps will not be available for download. Instead, the end-user is empowered to tune specifically for the fuel blend at their favorite fuel source using AccessTUNER software and data-logging to ensure proper performance. This also allows the end-user to blend different fuels to their liking and quickly tune for it. The BMW AccessTUNER Help Guide has been updated to include Fuel Scalar table descriptions as well as a reference chart for estimated Fuel Scalar values for different blends of ethanol and gasoline.

To update AccessTUNER and acquire the latest Fuel Scalar tables, simply open the software, click on Help in the menu bar, select Updates and click Check for Updates. In the pop-up window, check the Beta Software box in the lower right corner. Click the Get Updates button and follow on-screen instructions to complete the software upgrade and start tuning for alternate fuels!

I've tuned a few 700whp Civics, STI's, Evo's on E85 and I like to be on the conservative side. I found the beauty of E85 allowed me to run richer AFR's (11-11.3afr) and net basically the same power as a 12.0afr pull.. ~~~~HP loss was VERY minimal~~~~ These cars even picked up TQ with the richer AFR so why not build in a safety margin and run the richer AFR's if your fuel system can support the flow.. Timing wise I would leave it the same as pump/meth.. E85 is a faster burning fuel and the car will naturally pick up power compared to pump gas, all things equal......Now with the N54 platform and DI I would love to see some dyno results..!

This is the million dollar question... STI's, Evo's, etc all upgrade their injectors and fuel pump capacities when switching over to corn. There is basically no market for these components on the N54, so we need to know whether the DI hardware and the HPFP are up to the task to flow more fuel required to support 100% E85.

I've tuned a few 700whp Civics, STI's, Evo's on E85 and I like to be on the conservative side. I found the beauty of E85 allowed me to run richer AFR's (11-11.3afr) and net basically the same power as a 12.0afr pull.. ~~~~HP loss was VERY minimal~~~~ These cars even picked up TQ with the richer AFR so why not build in a safety margin and run the richer AFR's if your fuel system can support the flow.. Timing wise I would leave it the same as pump/meth.. E85 is a faster burning fuel and the car will naturally pick up power compared to pump gas, all things equal......Now with the N54 platform and DI I would love to see some dyno results..!

Thanks for the feedback.

I know E85 tuning strategy doesn't necessarily carry over across platforms, and after seeing Shiv's log of a 50/50 E85 map running 12.5 AFR across the board I started questioning the approach as again, I'm a total n00bert to DI tuning. Guess I will start logging and testing, but I'm still hoping PTF and/or Cobb can give me some E85 cliff notes on this platform.

The DME is setup differently, but the single value scalar is a perfect, simple table to correct your fuel trims. If you try it, you'll see that your fuel trims will still be at (or close to) zero in the top end.

Great now that we have the scalar, how about VE/load adjustments in the future... like for different hardware. I thought you all were doing this already for varying stages?

I may be understanding this incorrectly, but was thinking of a chart/spread sheat/scalar that would show what type of timing curve on could run on varios levels of octain?

I'm still curious to see if we continue to add advance to the point where we reach and then exceed MBT with no timing corrections. If this is the case, tuning for timing will actually require some intelligence and access to either a dyno, or a good stretch of road and a good dyno calc tool. Too many variables to list timing advance as being appropriate for X octane, but for straight E85 I'd probably start with the timing curves you typically see from piggies running aggressive tunes - 10ish rising to 14ish.

I'd still love to see a screenie of a timing table for a straight E85 tune, FBO stock turbo no meth, running at around MBT through the load curve. Anyone want to post one up??

This is all very exiting. I just ordered a Cobb AP and a couple of maps for E85/Vpower mix as well, I also run around a 50/50 mix. I have maxed the JB4 out with my RB's, but it's holding 17 psi beautifully, and timing is constantly in the 10-14 range as well, but it is leaning out a bit. Hence the Cobb

I may end up going for a 100% E85 map, but I'd like to take it one step at a time to see how the car copes. So far I have to say it is loving the E85/Vpower mix, and I hope to do some dynos next month with a few other local BMW guys. I hope I'll be able to join the next GTBoard event in Sweden, it would be nice to compare the RB car to Enrico and Big Toms cars.

This is all very exiting. I just ordered a Cobb AP and a couple of maps for E85/Vpower mix as well, I also run around a 50/50 mix. I have maxed the JB4 out with my RB's, but it's holding 17 psi beautifully, and timing is constantly in the 10-14 range as well, but it is leaning out a bit. Hence the Cobb

I may end up going for a 100% E85 map, but I'd like to take it one step at a time to see how the car copes. So far I have to say it is loving the E85/Vpower mix, and I hope to do some dynos next month with a few other local BMW guys. I hope I'll be able to join the next GTBoard event in Sweden, it would be nice to compare the RB car to Enrico and Big Toms cars.

Yes, I know meth is really helpfull, but for normal driving I'm only like max 8-10F above ambient temps, and even when I do 3+4+5+6 gear full pulls (and hit the rev limiter in 6th) and log, I hardly ever get above 120F IAT (in 80F weather) and timings stays at 13+ (no drops) and as soon as I let of the gas, it drops really fast down again to ~10F above outside temp. This is at 17 psi, it may of course change when (hopefully) I can bump that to 18.5-19 psi.

So IIRC I can start out as a decent base tune to run full e85 by say running stg2+sport and all I need to change is fuel scalier bank1 and 2 to 1.4?

Start with V402 stage 2 +FMIC aggressive and if your running 100% E85 start with the scalar at 1.300. Also add a few degrees of timing above 3k in the higher load columns. Log, add timin if no corrections, an start the process all over again.